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Vickers Hardness Testing of Metallic and Ceramic Materials
The Vickers hardness test was developed in 1924 as a method for determining a material’s
hardness regardless of an indenter’s size. It can be used for most materials, irrespective of
hardness, and has one of the widest scales among hardness tests. The test is governed by ASTM
standard E384 for loads ranging from 1 gf to 120 kgf. A typical Vickers hardness indentation can
be seen in Figure 1.
Figure 1. A typical Vickers hardness indentation in SS430.
The Vickers hardness test is performed by pressing a diamond indenter tip in the form of a
square-based pyramid into the sample at a specific load and then measuring the diagonal
distances of the square indent that is created. The Vickers Hardness value, HV, is obtained via
Equation 1,
Eq. 1
HV 
1.891F
d2
where F is the indenting force in kgf and d is the average diagonal distance of the indentation in
millimeters. The standard notation for reporting is HV followed by a number representing the
indentation load in kgf. For example, 20 HV8 indicates a Vickers hardness value of 20 kgf/mm2
under a load of 8 kgf. Different indentation loads are selected depending on the thickness and
volume of the sample that will be indented on.
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ebatco
Exponential Business and Technologies Company
Bridge You and Nano
______________________________________________________________________________
Vickers hardness testing is typically performed on samples that are too small or too thin to allow
for testing using a different method. Stainless steel alloy 430 is frequently used as a thin
protective liner for equipment used in moderately corrosive environments such as dishwashers,
chemical processing equipment, heat exchangers, etc. As such, Vickers hardness testing is an
appropriate method for testing SS430’s mechanical properties in many applications. Vickers
hardness data for fully annealed SS430 obtained using a CSM Micro Indentation and Scratch
Combi Tester (CSM Instruments, Switzerland) is given in Table 1.
Table 1 Vickers Hardness Data for SS430
Test
1
2
3
4
5
Average
S.D.
HV1 (kgf/mm2)
166.82
163.74
161.39
161.56
161.48
163.00
2.35
Vickers hardness testing is also frequently used to characterize ceramic materials. Silicon nitride,
Si3N4, is an engineering ceramic that is prized for its hardness, low coefficient of thermal
expansion, superior wear resistance and corrosion resistance. Since there are several different
methods of processing Si3N4, a Vickers hardness test can yield valuable information regarding
how the material was processed and its resulting properties. Vickers hardness data for Si 3N4
obtained using a CSM Micro Indentation and Scratch Combi Tester is given in Table 2.
Table 2 Vickers Hardness Data for Si3N4
Test
1
2
3
4
5
Average
S.D.
HV0.8 (kgf/mm2)
2189.97
2162.53
2305.83
2006.75
2040.34
2141.08
120.61
______________________________________________________________________________
Address: 7154 Shady Oak Road, Minneapolis, MN 55344, U.S.A.
Tel: +1 (952) 334-5486, Fax: +1 (952) 746-8086, Email: natlab@ebatco.com
www.ebatco.com